DE10027177A1 - Alignment of an inkjet writer having a cartridge for transparent fluid such as fixer by generation of a test pattern with neighboring regions having different reflection behavior that can be detected by a suitable sensor - Google Patents

Abstract

Procedure has the following steps: movement of the printer write head to pre-determined positions for printing of pixels of fixer and ink in adjacent positions; movement of an optical sensor to the pixel positions; printing of a pre-set test pattern in two positions that have different reflection behavior which can be detected by the sensor; determination of the difference between the two for alignment. An Independent claim is made for a test pattern for alignment of an inkjet head using transparent fixer or similar.

Description

The present invention relates generally to inks Jet printing technology processes and ink jet printing techno logie devices and in particular on a method and a device for aligning inkjet pens, the Fire droplets of a clear fluid.

The technique of inkjet technology is relatively good wraps. Commercial products such as B. computer printer, Graphic plotters (graphic drawing devices), copiers and faksi mileage devices use inkjet technology to create against a hard copy. The basics of this technology are for example in various articles of the issue of Hewlett Packard Journals, Volume 36, No. 5 (May 1985), Volume 39, No. 4 (August 1988), volume 39, No. 5 (October 1988), volume 43, No. 4 (August 1992), Volume 43, No. 6 (December 1992) and Volume 45, No. 1 (February 1994). Inkjet pre directions are also from W. J. Lloyd and H. T. Taub in Output Hardcopy [sic] Devices, Chapter 13 (Ed. R. C. Dur Beck and S. Sherr, Academic Press, San Diego, 1988) be wrote.

U.S. Patent No. 5,635,969 (Allen, Common Be delegated to the present invention and incorporated herein by reference), METHOD AND APPARATUS FOR THE APPLICATION OF MULTIPART INK-JET INK CHEMISTRY, um a multi-color inkjet printing system incorporates a printing element to apply an accurately measured amount of a colorless Predecessor or intermediate on a record me user interface. The intermediate fabric is conditioned or treated delt the media surface before attaching one or several dyes on the recording medium surface, to prevent ripples or waves, and to prevent drying Reduce time while recording media  Independent surface for even point gain handled by the media composition. The U.S. Pa tent registration Ser. 09 / 069.717, entitled REACTIVE INK SET FOR INK-JET PRINTING, by Askeland u. a. and the U.S. Patent Application Ser. 09 / 069,616, entitled MULTI-CHAMBER FLUID SUPPLY, from Askeland u. a., and ver related applications cited therein are also of the Joint Agents of the Present Invention and are incorporated herein by reference. in the following are clear fluids that are used to make up the Drying time and affect the durability, and order to prevent curling and rippling of the print medium, commonly referred to as a "fixer".

U.S. Patent No. 5,600,350 (Cobbs et al., Issued to ge joint agent of the present invention and is incorporated herein by reference), MULTIPLE INKJET PRINT CARTRIDGE ALIGNMENT BY SCANNING A REFERENCE PATTERN AND SAMPLING SAME WITH REFERENCE TO A POSITION ENCODER, is a method and an apparatus for Multi-inkjet cartridge alignment by scanning a reference pattern and scanning with an optical sensor intended. In fact, a given test pattern is ge prints and actual print image data are compared to to determine a missing fit of the cassettes. A SYSTEM AND METHOD FOR ESTABLISHING POSITIONAL ACCURACY IN TWO DIMENSIONS BASED ON A SENSOR SCAN IN ONE DIMENSION is in the U.S. 5,796,414 (Sievert et al.) Provided the same the joint proxy is hereby delegated and is incorporated by reference.

Although the method of printing a test pattern and optical detection of actual positions of an el ment of the pattern on the print medium a valuable work is evidence for dyes that have a sufficient Re inflection difference with respect to the background measurement diums, there is a problem with dyes that have a reflectivity that is only a  few percent of the reflectivity of the empty medium differs. In U.S. Patent Application Ser. 08 / 636,439 for SYSTEMS AND METHOD FOR DETERMINING PRESENCE OF INKS THAT ARE INVISIBLE TO SENSING DEVICES (Nelson et al., of the Joint Agents of the Present Invention and incorporated herein by reference) is a System and method for determining the presence of Inks that are visible to the normal human eye however, optically "invisible" for sensors are provided.

The object of the present invention is a Method for determining position correction factors for at least one inkjet writing device for a clear fluid, a test pattern for aligning a print head for clear fixer, a device for alignment a printhead for clear fixer and inks to create ray pen hard copy device that he possible that an inkjet print cartridge that a cl res fluid prints on the print medium, is aligned.

This task is accomplished by a method for determining Po sition correction factors according to claim 1, a test pattern to align a printhead for clear fixer Claim 7, a device for aligning a pressure Clear fixer head according to claim 9 and an ink beam-pen hard copy device according to claim 13 solved.

The present invention recognizes the basic aspects thereof Method for determining position correction factors each Weil for at least one inkjet writing device for clear fluid and at least one inkjet pen device for dye used for printing on a be adjacent positioned media are attached and the use a predetermined print pattern. The procedure around summarizes the following steps: attaching the inkjet pen device for clear fluid and ink jet writing device for dye in predetermined fixed positions relative to each other for printing pixels on the neighboring one  positioned print medium; Attach an optical detector solution device in a predetermined fixed position right relative to the inkjet writing device for clear Fluid and the ink jet writing device for dye; Printing a first predetermined pattern in predetermined ones Target regions on an empty print medium by firing a writing device; Printing a second predetermined pattern on the print medium by firing from the other ren writing device, such that the first printing regions superimposed on the first predetermined pattern, and the second pressure regions substantially adjacent to the first regions occur such that the first regions and the second regions reflectivity differences have by the optical detection device are recognizable; Capture the first regions and the second Regions with the optical capture device to collect data to get, which represents the reflectivity differences put; and determining a position difference between compared to the first regions and the second regions predetermined target region positions of the first predetermined Pattern.

Another present aspect sees the present inventor a test pattern for aligning a printhead for clear fixer of a first inkjet pen, the trop fired a clear fixer with a printhead a second inkjet pen, the drops of a color fired before, the pattern being at least one series of position calibration marks of a clear fixie rers on a print medium through the first inks beam pen are formed, and at least one dye on the series of position calibration mar clear fixer and on regions of pressure mediums is applied adjacent to the markings, where when a dye is applied to the markings, and the regions of the print media that are adjacent to the markie different reflectivity coefficients have ten.  

In another basic aspect, the present invention provides a device for aligning a printhead for clear fixer of a first ink jet pen that fires drops of a clear fixer with printheads of at least one ink jet pen 115 that fires drops of color ink, wherein the device optical sensor devices for projecting light and receiving light, for which the clear fixer is not optically recognizable when it is placed on an empty print medium, the color ink having a reflectivity that is optically recognizable if compared to the empty print medium, a device for exposing the print medium to the optical sensor while the sensor is operating, a first print head for printing a predetermined fractional fill pattern on a first region, the first ink jet pen dropping the clear Fixierers fires a second print head f for printing on the print medium with color ink from the at least one inkjet pen, the drop of color ink both superimposed on the fractional fill pattern and the region adjacent to the fractional fill pattern on the empty print medium, such that the clear fixer flows with the superimposed color ink converts the fraction fill pattern into a fill pattern that has a different reflectivity than the regions adjacent to the fraction fill pattern and has means for comparing data representing the predetermined fraction fill pattern with the actual position of the first region .

Another present aspect sees the present inventor an inkjet pen hard copy device for printing bringing droplets of a marking fluid onto target pixels a print medium, wherein the hard copy device a first printing device for printing a clear fluid a pressure medium in a pressure zone of the device, a second printing device for printing ink on the print  medium in the pressure zone of the device, a determination device for determining the presence of a pressure the print medium, which is an optical detection device for Aiming light at the print medium and for detecting Reflections of light from the print medium, the Determining device the reflectivity differences between the ink on the print medium and the ink that overlies the clear fluid on the print medium, and a positioning device for locating special Regions of patterns that are through the first print direction and the second printing device are printed, with the patterns of both regions of ink on the print me dium as well as regions of ink over the clear fluid are placed on the print medium.

It is an advantage of the present invention that it is a method and an apparatus for optical determination of deposits of a clear fluid without ul traviolet, infrared, fluorescent devices or the like Lich withdrawn specialized device for detection fen.

It is an advantage of the present invention that it is provides a solution that does not require additional components calls into an inkjet hard copy device must be installed.

It is another advantage of the present invention that through the use of existing product devices the manufacturing effort is not increased.

It is another advantage of the present invention that using existing product devices same the potential of an additional complexity and one accompanying reduction in reliability reduced.

It is another advantage of the present invention that same the manufacture of products with a minimized  Size allowed.

It is another advantage of the present invention that it provides a product that can be delivered to a plurality of Functional designs are customizable.

Preferred embodiments of the present invention are appended below with reference to the Drawings explained in more detail. Show it:

Fig. 1 is a perspective view of an ink jet printer according to the present invention;

FIG. 2 shows an optical detection unit used in accordance with the present invention shown in FIG. 1; and

FIG. 3 shows a test pattern for scanning with the optical detection unit shown in FIG. 2, which is used according to the present invention shown in FIG. 1.

It will now be detailed on a specific execution example of the present invention referenced for the inventors the currently best conceivable way to Practicing the invention. Alternative execution Examples are briefly described as applicable.

Fig. 1 illustrates an ink-jet hard copy apparatus, in this exemplary embodiment, a Computerperi ripherals color printer 101. A housing 103 includes the electrical and mechanical operating devices of the printer 101. Operation is through an internal electronic controller (typically a microprocessor or a printed circuit board that is controlled by an application specific integrated circuit ("ASIC"), through appropriate wiring (not shown) It is well known to program the imaging, printing, media handling, control functions and logic with firmware or software instructions for a conventional microprocessor or general purpose microprocessor or ASICs Cut sheet printing media 105 , hereinafter commonly referred to as "paper" regardless of the media actually selected by the end user, is loaded by the end user into an input tray 120. Sheets of paper are then subsequently passed through an appropriate, inner paper path transport device (not shown) to egg ner in neren printing station platen or "printing zone" 107 supplied, in which graphic images or alphanumeric text using the known color imaging or text reproduction using dot matrix manipulation methods are generated. A carriage 109 attached to a slider 111 moves over the sheet of paper that is conveyed to the printing zone 107 . An encoder strip 113 and associated position encoding devices on the carriage 109 and as part of the controller are used to track the position of the carriage 109 at any time (see e.g. a SINGLE CHANNEL ENCODER SYSTEM and a SINGLE CHANNEL ENCODER WITH SPECIFIC SCALE SUPPORT STRUCTURE by Majette et al. in U.S. Patent Nos. 4,789,874 and 4,786,803, assigned to the assignee of the present invention and incorporated herein by reference). A set of individual ink-jet writing devices, "pins", 115 K, 115 C, 115 M, 115 Y, 115 M, each having ink jet printheads as is known in the art (not tive visible in this perspec) , are releasably attached to the carriage 109 in fixed positions for easy access and repair or replacement. Each printhead device is adapted for "jetting" tiny droplets of ink or other fluids (such as, for example, in Allen above) to form dots on adjacent paper in printing zone 107 . Refillable or replaceable ink supply cartridges or "containers" 117 K, 117 C, 117 M, 117 Y are provided; Generally, a full color ink jet system uses inks for the subtractive primary colors cyan, yellow and magenta (CYM) and a true black (K) ink. However, it should be noted that additive primary colors - red, blue, green - or other dyes can be used. This set also includes a pin 115 F and a cartridge 117 F for a clear fluid fixer "F" before. Pins 115 are coupled to respective cartridges by a flexible hose assembly 119 . It should also be noted that the present invention can be implemented in a hard copy apparatus that uses interchangeable, independent supply ink jet cartridges as are known in the art. As soon as a printed page is finished, the paper sheet is ejected onto an output container 121 . It is common in the art to refer to the pen movement direction as the x axis, the paper feed direction as the y axis, and the ink drop firing direction as the z axis.

FIG. 2 is a schematic illustration of an optical sensor unit used in accordance with the present invention. Ink jet nozzles of the printheads lie generally in line with the sensor module 210 in the x-axis by the module 210 being suitably attached to the carriage 109 ( FIG. 1). The sensor module 201 detects optically visible pen marks on the paper - namely, ink drops or sets of ink drops - and provides electrical signals to the controller and alignment algorithm that indicate the fit of the portions of the printed pattern generated. An optical component holder 203 contains a lens 205 . In the exemplary embodiment shown, one or more light emitting diodes ("LEDs") 207 are attached at an angle to the plane of the print zone 107 ( FIG. 1). As will be appreciated by those skilled in the art, it is known in the art to use refraction and diffusion devices to align the light emitting and photosensitive components.

The LEDs 207 project light onto a test pattern "TP", which is printed on the paper 209 with the printheads, and the light is then reflected to a photodetector 211 . Known optical detection and signal processing methods are used in which the actually detected pattern is compared with the expected test pattern (see e.g. Cobbs et al., Above). For further details relating to a specific multifunction optical sensor module useful in accordance with the present invention, reference may be made to U.S. Patent Application Ser. 09 / 183,086 (filed October 28, 1998 by Walker et al., Assigned to assignee of the present invention and incorporated herein by reference).

Fig. 3 is a schematic illustration of a test pattern of an exemplary embodiment according to the present invention, which is used to align the printhead for clear fluid with other ink stick printheads 115 . An actual test pattern is colored and is represented by the shadings indicated in this exemplary black and white reproduction.

A predetermined pattern 301 of bars 305 or other geometric shapes suitable for the particular implementation is placed on paper using only a clear fixer. The bars 305 in the known test pattern 301 are actually a series of position calibration marks; that is, from the database containing the pattern and position of carriage 109 as determined by encoder 113 , the bars printed from the pattern data are at the printhead position of pen 115 F for clear fixer at the time point of firing towards a specific target image element ("pixel") on paper. This particular pattern, implemented for a specific embodiment or purpose, need only consist of a fractional fill pattern created on the blank paper.

Then, ink from one or more of the pens is placed over the test pattern of the clear fixer consisting of bars 305 and regions 303 between the bars. The next swath height (which is equal to the printhead height) of a pattern of fuser bar 305 is printed. The process continues for any ink of interest or combinations of ink of interest. It should be noted that there are specific chemical examples in which the fixer is applied after the dye.

The result is a test pattern in which the color inks will diffuse into the paper in regions 303 where there is no fixer, namely between the geometric bars 305 . This leads to less vivid color regions 303 between the fixing bars 305 . It has been found that the reflectivity of overlying fixer bars 305 is a noticeable difference from diffusion regions 303 , in which no fixer was deposited with a dye prior to overprinting.

Other colors can be made by mixing inks while moving. Depending on the wavelength of the LED 207 , special colors that the LED is more sensitive to can be used.

The generated data, namely the actual position of the bars 305 of pixels having a fixer thereon, which is derived from the data of the encoder 113 and the data of the sensor 201 , is compared with the expected position based on the given test pattern data . The alignment algorithm determines specific nozzle firing misalignments, and the results are used by the printer's printing algorithm to operate the print jobs. Corrections of deviations in the carriage movement x-axis and the paper movement y-axis can be calculated. For example, Cobbs' algorithm, among others, above, works for offsets between pens that can be corrected along the paper feed y-axis by selecting certain printhead nozzles for activation. A further correction could be applied by masking the data as being between bands of the marker implementations, as taught by Sievert et al. Above.

The present invention provides a test pattern in which Regions with improved contrast that have a fixer on them be overlaid by a sensor-visible ink, because the buildup of fixer and dye is interrupted and not consistently over an entire test pattern are.

Claims (17)

1. A method of determining position correction factors for at least one clear fluid ink jet writing device and at least one dye ink jet writing device, each mounted to print on an adjacent positioned printing medium, and to use a predetermined printing pattern , with the following steps:
Mounting the ink jet writing device ( 115 F) for clear fluid and the ink jet writing device ( 115 x) for dye in predetermined fixed positions relative to each other for printing pixels on the adjacent positioned printing medium;
Mounting ( 109 ) an optical detector ( 201 ) in a predetermined fixed position relative to the clear fluid ink jet writing device and the dye ink jet writing device;
Printing a first predetermined pattern in predetermined target regions ( 305 ) on blank print media by firing from a writing device;
Printing a second predetermined pattern on the print medium by firing from the other writer such that first print regions (bars) appear superimposed on the first predetermined pattern and second print regions ( 303 ) occur substantially adjacent to the first regions such that the first regions and the second regions have reflectivity differences that are recognizable by the optical detection device;
Detecting the first regions and the second regions with the optical detection device to obtain data representing the differences in reflectance; and
Determining the position difference between the first regions and the second regions compared to predetermined target regions of the first predetermined pattern. 2. The method according to claim 1, wherein the step of printing a first predetermined pattern in predetermined target regions ( 305 ) on an empty print medium by firing from a writing device further comprises the following step:
Applying droplets of clear fluid from the clear fluid ink jet writing device. 3. The method of claim 2, wherein the step of printing a second predetermined pattern on the print medium by firing from the other writing device such that the first printing regions (bars) are superimposed on the first predetermined pattern, and the second printing regions ( 303 ) occur substantially adjacent to the first regions, such that the first regions and the second regions have differences in reflectivity that are detectable by the optical detection device, further comprising the step of:
Application of droplets from the ink jet writing device for dye. 4. The method of claim 1, 2 or 3, wherein the step of printing a first predetermined pattern comprises the step of:
Moving the clear fluid ink jet writing device over the print medium and firing droplets of clear fluid toward predetermined target pixels to produce a pattern of a series of position calibration marks ( 305 ). 5. The method of claim 1, 2, 3 or 4, wherein the step of printing a first predetermined pattern further comprises the step of:
Form a series of position calibration marks for each ink jet writing device for dye. 6. The method of claim 5, wherein the step of printing a second predetermined pattern comprises the step of:
Printing a respective ribbon of dye over and between each series of position calibration marks from each of the respective ink jet writing devices for dye. 7. A test pattern for aligning a printhead for clear fixer of a first ink jet pen that fires drops of a clear fixer with a printhead of a second ink jet pen that fires drops of dye, with the following features:
at least one series of position calibration marks of a clear fixer formed on a print medium by the first ink jet pen; and
at least one dye applied to the series of position calibration marks of the clear fixer and to regions of the media adjacent to the marks, the marks having a dye applied thereon and the regions of the printing medium, which are adjacent to the markings, have different reflectance coefficients. 8. A test pattern according to claim 7, wherein the position Calibration marks provide data related to Corrections of deviations in an x-axis and an y-axis can be obtained. 9. Device for aligning a printhead for clear fixer of a first ink jet pen ( 115 F) that fires drops of a clear fixer, with print heads of at least one ink jet pen ( 115 ) that fires drops of color ink, with the following features :
an optical sensor device ( 201 ) for projecting light and for receiving light, for which the clear fixer is not visually recognizable when it is applied to an empty printing medium ( 105 ), where the color ink ( 117 KY) has a reflectivity points that is optically recognizable when it is compared with the empty print medium;
means ( 109 ) for exposing the print medium to the optical sensor while the sensor is operating;
first printhead means for printing a predetermined fractional fill pattern ( 305 ) on a first region with the first ink jet pen ( 115 F) firing drops of the clear fixer ( 117 F);
a second printhead device for printing on the print medium with color ink from the at least one ink jet pen ( 115 ), the drops of color ink both superimposed on the fraction fill pattern and on the region ( 303 ) which are adjacent to the fraction fill pattern on the empty print medium is fired such that blending the clear fixer with the overlaid color ink converts the fractional fill pattern into a fill pattern that has a different reflectivity from the regions adjacent to the fractional fill pattern; and
means for comparing data representing the predetermined fraction fill pattern with the actual position of the first region. 10. The apparatus according to claim 9, wherein the means for exposing the printing medium has a mounting, in which the first ink jet pen ( 115 F) and the at least one ink jet pen ( 115 ), which fires drops of color ink, firmly attached are, and are firmly aligned with the detection device ( 201 ) in a predetermined relationship to each other. 11. The apparatus of claim 9, wherein the mount is a moving carriage for carrying the first ink jet pen ( 115 F) and the at least one ink jet pen ( 115 ) that fires drops of color ink over predetermined ribbon positions of the print medium. 12. The apparatus of claim 10, wherein the means for comparing data representing the predetermined fractional fill pattern with the actual position of the first region comprises:
means for correlating data obtained by the sensor for corrections of deviations in a carriage movement x-axis and a paper movement y-axis. 13. An ink jet pen hard copy device ( 101 ) for applying droplets of a marking fluid to the target pixel of a printing medium, having the following features:
a first printing device ( 115 F) for printing a clear fluid ( 117 F) on a printing medium ( 105 ) in a printing zone ( 107 ) of the device;
a second printing device ( 115C MYK) for printing ink ( 117 CMYK) on the printing medium in the printing zone ( 107 ) of the device;
determination means ( 201 ) for determining the presence of pressure on the print medium, comprising optical detection means for directing ( 207 ) light onto the print medium ( 209 ) and for detecting reflections of the light from the print medium, the determination means reflecting differences between the ink on the print medium and the ink superimposed on the clear fluid on the print medium; and
position means ( 13 ) for locating specific regions of patterns printed by the first printing means and the second printing means, the patterns both regions of ink on the printing medium and regions of ink passing over the clear fluid on the printing medium are laid. 14. The apparatus of claim 13, wherein
the clear fluid is an ink fixer;
the first printing device ( 115 F) is an ink jet printhead for fixers for firing droplets of a fixer onto target pixels of the print medium; and
the second printing device ( 115 CMYK) is a plurality of ink jet inking printheads, each of which fires droplets of a different dye onto target pixels of the printing medium, the printhead for fixers and the inking printheads with respect to one another in predetermined positions in a printhead. Be moving car are firmly attached, which is assigned a position encoder ( 113 ). 15. The apparatus of claim 14, wherein
the optical detector includes a light emitting diode ( 207 ) for emitting light of a predetermined wavelength selected to determine the reflectivity of each different dye;
the determination device has a fixed attachment for the optical detection device, in which the optical detection device with respect to the print head for fixers and the inking print heads is fixedly attached in a predetermined position in the print head movement carriage which is assigned to the position encoder. 16. The apparatus of claim 13 or 14, wherein the patterns further include:
at least one series of position calibration marks ( 205 ) of a clear fixer formed on a print medium by the first ink jet pen; and
at least one dye (C / M / Y / or K) which is applied to the series of position calibration marks of the clear fixer and to regions ( 3 03 ) of the printing medium which are adjacent to the marks, whereby the markings have a dye applied thereon, and the regions of the printing medium adjacent to the markings have different reflectivities. 17. The apparatus of claim 16, wherein the position Calibration marks provide data that matters corrections of deviations in a car movement x axis and a paper movement y axis be.